Expansible clutch for wind motors



Oct. 16, 1934. c. A. PRESSNALL 1,975,891

EXPANSIBLE CLUTCH FOR WIND MOTORS Original Filed Aug. 1, 1928 3Sheets-Sheet 1 s-- t 6 5 5 a 7 f WEEK O a O Oi m" 9 fivenb'of: Z0 did?1% $522 Oct. 16, 1934. c. A. PRESSNALL 1,976,391

EXPANSIBLE CLUTCH FOR WIND MO'I 'CRS Original Filed Aug. 1, 1928 3Sheets-Sheet 2 32111910507": Cfizrles 14. Pessvz am 16, 1934- c. A.PRESSNALL EXPANSIBLE CLUTCH FOR WIND MOTORS Original Filed Aug. 1, 19283 Sheets-Sheet 5 57mTsfi.Press/zaZZ Patented Oct. 16,- 1934 V 1,976,891EXPANSIBLE CLUTCH FOR WIND MOTORS Charles Alvah Pressnall, Elkhart, Ind.

" Original application August 1,. 19 28, Serial No.

EN-T, OFFICE 296,705. Divided and this application Decem- H 'ber 15,1930, Serial N0. 502,556 v v 1 Claim. (01. 188-278 .The object ofmyinventionis to provide a novel. and. eflicient clutchfor wind motorsof the" type described in my application, Ser. 296,705, filed August, 1,1928,, now -=Patent 1,793,748, .datedFebruary 24, 1931, of which this.application is a division.

I attain the objectv of myinvention by the apparatus illustrated in theaccompanying drawings, in'which, l

Figure 1 is a view partly in section and partly in elevation of myinvention applied to a wind motor; a

Fig. 2 .is a transverse section through my expansible clutch;

Fig. 3 .is a top plan view of :the clutch in neutral position;

Fig. 4 is a detail of flat spring link 22; and

Fig. 5 is a horizontal section on line 5-5 of Fig.1.

Like numerals designate like parts in each of the several views.

Referring to the accompanying drawings, there is illustrated a windmotor which I have devised and to which my invention applies, having amain vertical shaft 1 to which is keyed or. other- Wiserigidly securedthe main frame members 2 and 2a. which are horizontally disposed andin-alinement with each other; one at the bottom and the other at the topof the-vanes 6 and 7; The frame membersare provided withcentrallylocated hubs 3 and 3a. q 7 g H The frame members 2 and 2a are preferablyribbed, as shown, and taper outwardly from the center to theirextremities where they are provided with hubs 4 and 4a which are drilledto receive the rods 5. These rods have a bearing fit in said hubs sothat they are freeto turntherein. I also provide the vertically disposedrods 8 to which the ends of the'vanes 6 and Tare attached. The outerextremities of bars 2 and 2a are provided with hubs 11, as shown inFig. 1. I provide curved arms 12 pivotally connected to the short arms13 which are attached to the rods 5, as

shown.

:As shown in Fig. l, I provide a clutch housing 15 provided with aninternal hub 14 which-is bored to provide a bearing fit on themainshaft 1. This hub section extends externally above the .topof thehousing to provide clearance between said housing and the lowerribportionof framemember 2a, whichrests directly on top of saidhub 1 4, asshown- The inside wallof this clutch housing is machined to receive theex pandingclutch members 21, which are also machined toprovide asuitable clearance between expansible their outside face and the innerwall of the housing when in normal position. The central portion ofclutch members 21 is bored to fit loosely the internal hub of thehousing, which tends to maintain the clutch members in a centralposition normally in relation to the said housing. The clutch members21v are spaced as indicated by numerals 9 and 10, as shown in Fig. 3.

i I provide suitable supports 17 to the top of which the tower cap 16 isfastened. I also provide-suitablycoiled springs 17a; positioned over therods or shafts 5 as shown in Fig. 5. The lowerend of each'spring extendsoutwardly and is operativelyconnected to the lower frame member whilethe opposite or upper end of each 7 spring engages collars locked to therods or shafts ,5. .I- alsoprovide a suitable brace member and bearing18 for; main shaft 1. The main shaft lat its lower end is provided witha suitable gear19 meshing with a second gear 20 on a-rod 29 I alsoprovide a suitable operating handle 25 for the clutch rod 24, as shownin Fig. l. @Themembers 21. normally rest on the top of the tower cap 16which is machined to receive the main shaft bearing 28 and the clutchrod 24. 8D

The clutch rod 24 is provided with a cam-like head- 23 which ispositioned within the space 10 between clutch members 21 and has itsbear.- ing inthetower cap or equivalent as illustrated. v I provide likeslots 26 in members 21 suitably shaped to receive the rolled ends 2'?and a portion of the body of the flat spring link 22, as shown in Fig.3, and which link functions to link the-spaced ends of the clutchmembers 21 together, as illustrated. .{Ihe normal position of the.clutch assembly isshownin Fig.3.. The housing 15 is free to turngon themain shaft 1 independent of the frame member 2a,.or conversely the shaft1 and the-frame member 2a are free to turn independently of clutchhousing 15. l Whena torsional efifort is applied to the clutch rod 24,the clutch members 21 are causedto-expand against the inner wall ofhousing 15. Now, assumingthe vanes arein the normal running position,namelyin the position shown in full lines in Fig. 5, but not rotating,and it is desired to causethe vanes to-assume the inoperatire position,,thecontrol or clutch rod is actuated by-meansof a lever orotherwiseineither direction, thus causing the clutch members 21 toexpand'and peripherally gripthe housing. Then the main shaftis rotatedslowly in. the direction of rotation normally. This may be doneeitheriby hand or power in anydesired or' conwith the main shaft.

ventional manner. This results in a pull on the curved arms 12,accomplished by such rotation through the medium of the expansibleclutch, which holds the clutch housing stationary while the curved armsand vane structure is thus rotated. The movement of the arms 12 and thepivotally connected short crank arms 13 is transmitted to, the verticalrods or. vane arm' shafts 5, to the lower ends of which crank arms 13are rigidly secured, and to the attached vane arms, thus causing thevanes to assume the neutral or out of the wind position indicated bydotted lines in Fig. 5.

When this position has been attained, the positions of the curved linksor arms 12 have brought their pivot points on a deadcenter line-with themain vertical shaft, in whichposition' the" vanes would be in the dottedline position illustrated in Fig. 5 and the torque of the tensionsprings applied to said arms on a dead center wither the vertical shaft,which would"lock same in this position. Hence, irrespective of thetension 'or power of the springs 17a, their. effort is on dead centerand they cannot pull the vanes back to the running position; However, ifthe clutch is again actuated, and the main shaft is turned.- backwardslightlyyin a direction oppositeto-normal rotation, the curved armfulcrum or point of pivoting will be forced oii from dead center and the'sp'rin'gs'will then force the vanes tothe normal running position,namely that shown in full lines in Fig. 5.;

If the-vanes are injthe normal-running position with insufii'cientwindto cause rotation, and the clutch is set tight the vanes will automatically move to v the neutral position or to- Ward the neutralpositionishow'n in dotted lines in Fig. 5) during periods of high wind.It a sufv; ficiently strong gust of wind should strike the 40 concavevane surface squarely, both vanes would be quickly forced totheco'niplete neutral position and held there by reason of the curvedarm fulcrums or pivot points being on dead center If the machine isrunning and it is'desired to bring it to a gradual stop, a relativelylight clutch action will accomplish the result, while a more vigorousclutch action will instantly cause the vanes to assume the inoperativeor neutral'position and stop rotation. This clutch structure, therefore,functions both-as a pull out device and brake, in one. 5

The device claimed is both abrake and-a clutch according tohow itisoperatedl For instance, if the clutch shoes are lightly forced'againstthe inside walls of the clutch housing a definite frictional effort isobtained betweenthese two mem-' bers, not sufiicient, however, toactually lock the two together but merely acting as a brake, therebygradually bringing'the rotating housing to a However, if the clutchshoes are forcibly pressed against the inner wall'of said clutchhousing'they grip same 'asaclutch with sufl'icient tenacity to hold theclutchhousing from rotatin and because the clutch housing is notkeyed orother wise rigidlyattached to the main shaft of the wind motor,saidsh-aft together with the main frame members, vanes; and associatedparts are free to continue their rotating; hence ,by'virtue of themechanical connection between the clutch housing and the 'vertical rods5,through-the crank arms "13 and curved armsjlg, the vanes andassociated parts are forced from the running position to "th epositionin which the ful-' crum centers or pivot points of the crank arms 13 andcurved arms 12 are on dead center, and because of this fact the appliedspring tension is exerted on the said members on a dead center whicheffectually locks the vane structure in its inoperative position.

It will be readilyunderstood that if the machine is .operating in a lowvelocity wind wherein its revolutions per minute and consequent momentumcould be comparatively low and if the operator desired to stop same, hecould apply the clutch gently and stop rotation within two or threerevolutions, or he could apply the clutch vigorously and stop rotationinstantly, or practically so, but in neither case would the vanesassumethe inoperative position as indicated in dotted'lines' in Fig. 5.However, if the machine is being driven by winds of high velocity andthe speed or revolutions per minute is sufficiently great, a vigorousclutch action will cause theclutch housing to remain practicallystationary for the moment, while the. vane'structure is pulled to theinoperative position. indicated by dotted lines in Fig; 5, by virtue ofthe momentum of said structure and associated parts overpowering thecounter action of spring tension. Thus in a period of extremely highwind or-dangerous storms it is possible to cause the device to assumethe inoperative position as indicated by simply exerting vigorous clutchaction as explained If the device were nothing but a brake there couldbe no actual locking of the clutch members and the housing and it is notmy purpose to limit the action of the device to that of a brake only. Itis imperative that the device must act as a clutch in the circumstancesabove described. a i

It will be apparent that the clutch members 21 cannot rotate as the cammember 23"acts'as a stop, and that when this cam member 23 is in neutralposition, as shown in Fig. 3, the central hub of housing 15 maintainsthe clutch member in a central position relative to the internal wall ofthe clutch housing, thus eliminat ing all friction in the normal runningposition. 1 I i 7 While the cam 23 is shown with substantially arectangular cross section, it is to be under stood thata'ny desired formof cam may be employed; also that any suitable brake lining or othermaterial may be aflixed to the periphery of the clutch member 15 to takethe wear or to increase the braking effect.

It is also to be understood-that'the main shaft and clutch rod may beextended to any desired location and that other minor details ofconstruction maybe varied without departing from the spirit of myinvention.

It will be understood that power is to be taken from the main verticalshaft by means of suit able gears, pulleys, or other-suitable means. I

With reference to the device 15,'21,'et'c. if the force applied wasrelatively gentle, the result would be a braking action whichwould'perinit frictional slippage between the inner wall of the housingand'the clutch members.' If-so-operated it functions to retard a movingelement, but if sufiicient force'is applied, the resultant action is nota braking effect but a clutch action wherein the frictional elements areforced rig idly against the inner housing wall in such man neras to gripand hold said housing'stationary while'the vanes and accessory partsofthe-wind motor continue to rotate approximately 90 de- Gil having aslotted portion, a clutch rod, a cam like head mounted on said clutchrod and disposed between the spaced ends of the clutch members to causesame to expand and clutch the housing when the clutch rod is manuallyoperated, said clutch members having slots, and a spring link havingrolled ends shaped to seat in the aforesaid slots in the clutch membersto link the spaced ends of the clutch members together.

CHARLES A. PRESSNALL.

